gps-details

Garmin Developer Tips - GNSS Configuration

Example Code

Use of standard GPS is not recommended on modern watches; all systems or all + multi-band are advisable.

Here is some example code to select the suitable GNSS constellations via Position.enableLocationEvents.

function startUpdates(options) {
    // Attempt to enable location events using the provided GNSS configuration
    var started = false;

    try {
        // This can fail with InvalidValueException if the GNSS combination is not supported
        Position.enableLocationEvents(options, method(:onUpdate));
        started = true;
    }
    catch (error) {
        System.println(error);
    }

    return started;
}

function startLocationEvents() {
    // Enable location events using the optimal GNSS configuration
    var started = false;

    // Enable continuous location tracking
    var options = {
        :acquisitionType => Position.LOCATION_CONTINUOUS
    };

    // Use configuration parameter for Connect IQ 3.3.6 and later (e.g. fēnix 6 + vívoactive 4)
    if (Position has :hasConfigurationSupport) {
        // GPS L1 + L5, GLONASS, Galileo E1 + E5a, and BeiDou B1I + B2a (e.g. fēnix 7 Pro + Forerunner 255)
        if (Position has :CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1_L5) &&
              (Position.hasConfigurationSupport(Position.CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1_L5)) {
            options[:configuration] = Position.CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1_L5;
        // GPS L1, GLONASS, Galileo E1, and BeiDou B1I (e.g. fēnix 7 + vívoactive 5)
        } else if (Position has :CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1) &&
              (Position.hasConfigurationSupport(Position.CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1)) {
            options[:configuration] = Position.CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1;
        // GPS L1 and Galileo E1 (e.g. fēnix 6 + vívoactive 4) - May be skipped in the simulator
        } else if (Position has :CONFIGURATION_GPS_GALILEO) &&
              (Position.hasConfigurationSupport(Position.CONFIGURATION_GPS_GALILEO)) {
            options[:configuration] = Position.CONFIGURATION_GPS_GALILEO;
        // GPS L1 and BeiDou B1I - Potentially redundant
        } else if (Position has :CONFIGURATION_GPS_BEIDOU) &&
              (Position.hasConfigurationSupport(Position.CONFIGURATION_GPS_BEIDOU)) {
            options[:configuration] = Position.CONFIGURATION_GPS_BEIDOU;
        // GPS L1 and GLONASS - Potentially redundant
        } else if (Position has :CONFIGURATION_GPS_GLONASS) &&
              (Position.hasConfigurationSupport(Position.CONFIGURATION_GPS_GLONASS)) {
            options[:configuration] = Position.CONFIGURATION_GPS_GLONASS;
        }
        started = startUpdates(options)
    }
    // Use constellations parameter for Connect IQ 3.2.0 to 3.3.5 (e.g. fēnix 5 Plus + vívoactive 3 Music)
    else {
        // GPS L1 and Galileo E1
        if (Position has :CONSTELLATION_GALILEO {
            options[:constellations] = [ Position.CONSTELLATION_GPS, Position.CONSTELLATION_GALILEO ];
        }
        // GPS L1 and GLONASS - Potentially redundant
        else if (Position has :CONSTELLATION_GLONASS) {
            options[:constellations] = [ Position.CONSTELLATION_GPS, Position.CONSTELLATION_GLONASS ];
        }
        started = startUpdates(options)
    }
    
    // Use standard GPS with versions prior to Connect IQ 3.2.0 (e.g. fēnix 5 + vívoactive 3)
    if (!started) {
        options = Position.LOCATION_CONTINUOUS;
        started = startUpdates(options)
    }

    return started;            
}

Test Cases

Supported API levels can be found on the developer page that lists compatible devices.

These test cases show the expected order of GNSS configurations for consideration by the above code.

API Level 3.1

There is no mechanism to choose the GNSS configuration with API level 3.1.

Note: Galileo and GLONASS are supported by these watches, but Connect IQ apps such as APPro Windsurf will be limited to standard GPS.

Watch	GNSS Chipset	Config
fēnix 5	MediaTek MT3333	GPS
Forerunner 645	MediaTek MT3333	GPS
vívoactive 3	MediaTek MT3333	GPS

API Level 3.2

Use the constellations parameter for API level 3.2.

Note: API level 3.2 is rare according to the developer page that lists compatible devices.

Watch	GNSS Chipset	Config 1	Config 2
Forerunner 645 Music	MediaTek MT3333	GPS + Galileo	GPS + GLONASS
vívoactive 3 Music	MediaTek MT3333	GPS + Galileo	GPS + GLONASS

API Level 3.3

Use the constellations parameter for Connect IQ 3.3.0 to 3.3.5, or the configuration parameter for API level 3.3.6.

Note: The configuration parameter is the only new feature of API level 3.3.6, according to Google.

Watch	GNSS Chipset	Config 1	Config 2
fēnix 5 Plus	MediaTek MT3333	GPS + Galileo	GPS + GLONASS
Forerunner 245	Sony CXD5603GF	GPS + Galileo	GPS + GLONASS
vívoactive 4	Sony CXD5603GF	GPS + Galileo	GPS + GLONASS

API Level 3.4

Use the configuration parameter for API level 3.4.

Watch	GNSS Chipset	Config 1	Config 2	Config 3
fēnix 6	Sony CXD5603GF	GPS + Galileo	GPS + BeiDou	GPS + GLONASS
Forerunner 55	Sony CXD56xxxx	GPS + Galileo	GPS + BeiDou	GPS + GLONASS
Instinct 2	Sony CXD56xxxx	GPS + Galileo	GPS + BeiDou	GPS + GLONASS
Instinct 2X	Airoha AG3335M	Multi-Band	All Systems	-

Note: The GPS + Galileo configuration may be skipped in the simulator, resulting in GPS + BeiDou being chosen.

API Level 5.0

Use the GNSS configuration parameter for API level 5.0.

Note: The majority of watches that supported API level 5.0 now support API level 5.1, except some Venu models + derivatives (e.g. D2 Air X10).

API Level 5.1

Use the configuration parameter for API level 5.0.

Watch	GNSS Chipset	Config 1	Config 2
fēnix 7 Pro	Airoha AG3335M	Multi-Band	All Systems
Forerunner 255	Airoha AG3335M	Multi-Band	All Systems
vívoactive 5	Airoha AG3335MN	All Systems	-

Note: The fēnix 7 Pro may skip multi-band / all systems in the simulator, resulting in GPS + Galileo being chosen.